Method of and apparatus for refrigeration



Oct. l0, 1939. I D KlLLEFFE-R 2,175,267

METHOD OF AND APPARATUS FOR REFRIGERATION Filed Oct. 9, 1934 2Sheets-Sheet l Oct. 10, 1939. D. H. KILLEFFER v 2,175,267 i METHOD oFAND APPARATUS FOR REFRIGERATION Filed Oct. 9, 1934 2 Sheets-.Sheet 2 I-2o aan jo INVENTOR Anna' Y vso moored occ' 1o, 1939 UNITEDl sTATEsPATENT oEFlcE I METHOD F AND APPARATUS FOB REFBIGEBATION novia n.mueller, Crestwood, N. Y.

Apouoouon october s, 1934. sox-m No. '147,548

. 16 Claims.

This invention relates to the art of refrigeration and more particularlyto the use of low temperature refrigerants, such as solid carbon dioxidewhich absorbs heat from the refrigerated space ata temperature-muchbelow that required to be maintained in the space.

One of the principal objects of the present invention is to provide anewA method of increasing the effective refrigeration available from lowtemperature ref rigerants by interposing between the refrigerated spaceand the low temperature refrigerant; a heat engine'which absorbs heatfrom the refrigerated space and converts part of it into work andtransmits the remainder to the Alow temperature refrigerant.

As a specific feature of my invention I may provide an apparatus in theform of a heat engine which is operated by an evaporated secondaryrefrigerant normally condensed by the low temperature primaryrefrigerant and use the work of such engine inthe refrigerated chamberto operate a fan, in which case the total amount of refrigeration is thesame as when using the primary refrigerant alone although the rate ofcooling will be increased and more uniform temperatures result. Anotherobject of my invention is to provide a heat engine operated by anevaporated secondary refrigerant normally condensed by a low temperatureprimary refrigerant such as solid carbon dioxide and evaporated bythesheat of a refrigerated space using the generated work to operate amechanical device beyond the refrigerated space or to operate acompression refrigerating system which may additionally cool therefrigerated space.

A further object of my invention is to provide a combined solid carbondioxide and mechanical compression refrigeration system for a chamber tobe refrigerated in which the total theoretical refrigeration is from twoand one-half to nine times the refrigeration effect of the dry icealone, such emciencies varying with the temperatureof the refrigeratedchamber.

Further objects and advantages of my invention will appear from thefollowing description thereof taken inv connection with the attacheddrawings which illustrate preferred forms of embodiment thereof, and inwhich:

Figure 1 is a side elevation with parts' in sec- .tion and partsdiagrammatically shown, show-` ing the refrigerator having a combinedlow temperature refrigerant cooling chamber and afmechanicalrefrigerator:

Figure 2 is a diagram` showing the relative efflciencies of the improvedapparatus at'various refrigerator temperatures Figure 3 is a diagram ofthe relative temperature positions of the respective element, and

Figure 4 is a partial vertical section of the up- (Cl. (l2-$1.5)

` per part of the refrigerator showing a combined low temperaturerefrigerant chamber and an interna] fan.

The use of solid carbondioxide commonly known as dry ice" and other lowtemperature refrigerants of this type is especially desirable for manytypes of refrigeration because of their economy, ease of handling andthe possibility of obtaining lower temperatures 'than could normally beobtained by water ice. Such refrigerante have certain disadvantages andit has heretofore been impractical to use the available energy in theheat flow from normal refrigerator temperatures of 30 to 50 F. totemperatures of 110 F. In fact it has been common practice to blanket orinsulate the low temperature refrigerating chamber because suchtemperatures were so low as to be entirely undesirable in commercialpractice.

Another objection to the use of low temperature refrigerants is that arefrigerator normally requires but a small volume of refrigerant and therate of heat transfer to the refrigerated space is rather poor unlessartificial air currents are set up and a fan for this purpose decreasesthe amount loi? available refrigeration by the heat equivalent of thepower required to operate the fan. y

y I have found that I can materially increase the cooling or heatexchange efficiency of low temperature refrigerants and obtain otherbeneficial results without any power expenditure and at relatively lowinitial cost of the low temperature refrigerants'. Dry ice or vsolidcarbon dioxide which has a temperature of approximately F., isfrequently used in present day 'refrigerators and although I shall referto it specifically, it is to be understood that I amnot limited to it asother low temperature refrigerante operate substantially the same. Withsolid carbon dioxide at- -110 F. and refrigerator temperatures usuallyin the range of about 30 to 50 1"., depending on the nature of thematerials to be kept cold, the difference in temperature is considerableand the energy available, due to the flow of heat through this rangealthough not heretofore used successfully is very substantial.

I have discovered that I can materially increase the total amount ofrefrigeration normally obtainable from a quantity of low temperaturerefrigerant such as solid carbon dioxide by taking advantage of thephysical fact that the flow of heat from a higher to a lower temperatureisa potential sourceof energy. If, therefore. this potential energy canbe converted into mechanical energy and dissipated outside of therefril'erator chamber, this is an additional amount 0f energy given upby the refrigerated chamber and as there can be no loss with respect tothe initial value of the low temperature refrigerant.

' which is also in the refrigerated chamber, I am In the usual case,however, no external work is done, the value of W is 0 and thetheoretical efciency is one. Even if there is work done by the fiow ofheat, it is dissipated in the refrigerator chamber and no beneficialeffect is realized.

YI propose to use this potential energy, convert it into mechanicalwork, and dissipate the work outside of the refrigerator chamber, or Imay use this mechanical work to operate an additional refrigeratingsystem or I may dissipate the energy in aiding heat transfer within therefrigerator Without loss of refrigerating efdciency as compared toprevious systems. By dissipating the work W outside of the chamber, Ihave increased the amount of heat Q given up by the refrigerator toinclude in addition to the amount normally absorbed by the solid carbondioxide or other low temperature refrigerant Qc, the heat equivalent ofthe work W. 'Ihe quantity Qc which is the amount of heat absorbed byeach unit of solid carbon dioxide or other low temperature refrigerantis fixed and Q will vary depending on the apparatus used. In such cases,

the efl'iciency will always be one or more.

Although there is a considerable temperature differential through whichthe heat flows, it is essential that the work which can be done beconverted by an efficient mechanism. For my purpose, I find that a heatengine of the reciprocating or turbine type is most suitable and that Ican obtain highly desirable benefits from it. Furthermore, bycontrolling the operation of the heat engine, I am able to control therate of evaporation of the secondary refrigerant and therefore theamount of refrigeration in the refrigerated chamber.

One form of apparatus which lis suitable to carry out the features of myinvention is shown diagrammatically in Figure 1, and the data ofoperation are generally illustrated on Figures 2 and 3. In Figure 1, therefrigerator is generally shown as having insulated walls I0 and a re-`frigerated chamber I2 which is adapted to be maintained at any desiredtemperature which varies ordinarily from 30 to- 50 F. The refrigeratoris provided with a low temperature refrigerating chamber I4 which isinsulated from the chamber I2 by the wallsl I6 and preferably thischamber has a hollow wall 2G through which a suitable secondary'refrigerant may pass. If

dry ice or solid carbon dioxide is used as the primary refrigerant itmay be placed in the I' 'chamber I 4v through the insulated door 23 in awell known manner.

The secondary refrigerant surrounding the ,dry icechamber may be of anysuitable type such as ethylene oxide, anhydrous ammonia, or

other low boiling point liquids which are diffl-i cultly condensible andwhose freezing point is not above the temperature of the solid carbondioxide or other primary low temperature refrigerant used in the chamberI4. The refrigerant will collect when condensed in the sloping bottom ofthe chamber from which it will flow through the valve 22 by gravity intothe evaporator 24. The valve 22 is preferably a check valve so that theliquid cannot return under higher pressures. y l

The evaporator 24 is exposed to the heat of the chamber I2 and may beprovided with fins on its surface to secure an easier transfer of heatfrom the refrigerator space to its contents. It is conneoted in a closedcircuitwith the refrigerant chamber 20 through'the heat engine 26, whichmay be of any suitable pressure type, such as reciprocating, turbine orother type. The heat engine 26 is adapted to operate a shaft 21 throughwhich the mechanical energy may be transferred outside of therefrigerator compartment I2 and if desired, it may be provided with aflywheel for regulating the operation.

In operation, the refrigerant in the chamber 20 will normally becondensed by the low temperature of the solid carbon dioxide. The liquidwili then be free to pass through the valve 22 into the evaporator 24.Due to the high temperature of the evaporator, the liquid will bevaporized and the pressure generated will be sufiicient to operate theengine 26.

The exhaust vapor from the engine 26 is conducted through the pipes 28back to the hollow chamber 2t; where it accumulates until the pressurein the evaporator equalizes which occurs after complete evaporation ofthe liquid in the evaporator. Then after the liquid has condensed in thechamber 20 and passed through the one way valve 22 the cycle ofoperation begins again. It is to be understood that the hydrostatic headof the liquid and the resistance of the valves and the engine will be socorrelated that the flow will occur in this manner.

The work done by the engine 26 is conducted out of the refrigeratorcompartment I2 by the shaft 21- and may be used for any suitablepurpose. Merely dissipating it in external friction will increase theefficiency of refrigeration of the dry icey in which. any value for W orWork must necessarily increase the value of Q absorbed from therefrigerator chamber I2. Preferably, however, I provide a compressionrefrigeration circuit including the compressor 30 which operates on asuitable refrigerant such as ammonia which in turn passes as a liquidthrough the condenser 32 to the expansion valve 33 for a subsequentexpension in the evaporator 35 which is within the refrigerator chamberI2. This evaporator will withdraw a, considerable amount of heat fromthe 'chamber as the amount of heat Vtransferred to thel atmosphere bythe condenser 32 in a compression system is much greater than the energyVconsumed in its operation. The expanded gases will return to the pump30 for further compression to complete the cycle.

From the following tables it will be seen that the refrigeration due tothe compression refrigeration system may be from one and one-half to iisreturned in the form of refrigeration to the system with a very highoverall result, and although the efficiency of the compressor maysomewhat reduce the maximum theoretical amount of refrigeraas willappear from the prior formula eight or more times that of the simplesolid carbon absolute and varying temperatures of the refrigeratorchamber. -No-attempt has been made to show results with extreme accuracyas theonly object is to illustrate the lgeneral principles involved. Itis to be understood therefore that the relative effects are inconformity with known data and the precise mathematicaldetails are notused The accepted formula for the work available in a refrigeratorhaving a temperature T1, and being cooled by a refrigerant at atemperature Tn may be expressed as follows where Q1 is the quantity ofheat absorbed at T1, and Q: is the quantity of heat rejected at Ta. Thequantity of heat Q: is identical with the quantity Qc in Equation 1"above. 1 l T|-Tn=Qi-Qz (2) y T, ma, Now by substituting the temperaturesof T1 as 490 and Tr as 350, the work done is 49.0 350 =lwork The valueof Q1 is 25o n, t. u.'/# solid carbon dioxide based on the latent heatof sublimation of solid co1 at 1o9.6 F.

`work=250 2/5=1oo B. t. u.

If the temperature T i's selected ,for varying refrigerator temperaturesof F., 30 F., 10 F., 0 F. and 20 F., the range for commercial practice,then by using the corresponding absolute temperatures it will be foundthat the work available and the total refrigeration available when thelwork W (equal to Qi-Qz) is expended outside the refrigerator compartmentl2 is as follows:

T l Qi-Q: Q1 Total ssc au 14s aso :iso 14o asc aan 134 :so aan m zso 31412s This is the basis for Curve B.

' If nowthe available work is converted `into 'refrigeration bymechanical compression, the

,same formula is proper although the symbols have a slightly differentsignificance.

L If T1=temperature of the refrigerator and T=condenser temperature(outside air) the formula may be expressed as foliows:'

4) Ln-5,1 l t Now assuming 'r1 to be vso" r. or`49o absolute and T. tobe F. or 540 absolute, and AW= B. t. u. at 30 F.

then.

and the total refrigeration is For different refrigerator temperatures,the quantity AW varies according to Table 3, and

In a schematic form, as shown in Figure 3, it

willclearly appear that the heat of the refriger ated chamber which maybe represented at i2 and as having a temperature of 40 F., will give upa quantity of heat Q which heat will cause such a pressure on thesecondary refrigerant that`it will operate the compressor 2i. Theexpanded refrigerant will then pass to the condenser or primaryrefrigerant chamber I4 which being at the extreme temperature of 110, ifcontaining solid carbon dioxide, will cause 'a condensation and heatexchange. It is to be noted that as the primary chamber is also withinthe refrigerator walls I0, there will be a direct entry of heat Q1 intosuch compartment.

Now due to the operation of the heat engine 2|, there is a certainamount of heat or equivalent work Q'. which goes out of the compartmentand is dissipated. This is in accordane with Formula l Q==Q+W and as Qcis fixed as the heat required to sublime the low temperature refrigerantsuch as solid carbon dioxide, the amount of heat which can be extractedby the combined system is greater than the heat which could normallybe'extracted by the low temperature refrigerant alone.

When the compressor refrigerator cycle is operated, the heat which isrequiredr to operate the compressor 26, W is dissipated by the condenserl2 and this condenser similarly dissipates the heat of compression whichenters the evaporator Il. As heretofore shown, this total heat may befrom two and a half to nine times the heat which is absorbed by thesolid carbon dioxide. The elciency'therefore of the combined systems isgreater than one and at normal refrigerator temperatures of 30 F., tov50 F., this is greater than seven times the solid carbon dioxiderate.

It may be found that the combination compression system may involve undue expense in .some small installations.`- Insuch installationshowever, it is commento use a circulating fan to4 promote heat exchangeand such fans are oi .course supplied with outside energy, "",which isdissipated within the refrigerator. Such ar rangement is justified as afrule since the exposed portion oi' dry ice is usually small andremoteparts of the refrigerator do notbecome adequately cooled without forcedcirculation.

In a modified form of apparatus as shown in @-Figure 4, the availableenergy of the heat flow is used to operate a circulating fan andinasmuch as no outside energy is added,the efiiciency of cooling is' notreduced and, at the same time the rate of cooling Vis increased. Theapparatus is The low boiling point secondary refrigerantV 7o y similarto-that shown in Figure l and includes c V in the hollow walls 29surrounding the primary refrigerating chamber empties into theevaporator 4l) which may be of modiiied tubular form. This evaporator isprovided with a suitable check valve 42 allowing the liquid to move intothe evaporator from the secondary rerigerant charnber 20 but notallowing it to return. The evaporator, All may be of the self-bleedingtype having the bleeding device di ir" desired.

A turbine motor M of the heat engine type is used in this modified formoi embodiment and is placed in the gas discharge circuit leading fromthe evaporator 413 to the secondary reu irigerant condenser it. Thismotor lvlis connected in 'turn to a ian iii mounted within therefrigerated chamber l2 in a suitable position' to facilitate heattransfer.

ils heretofore described, the secondary refrigerant enters theevaporator :lil and in a similar manner will loe evaporated to createsunlcient pressure ior rotation oi the ian and useful work. The exhaustrorn the motor il@ will return as gas to the condenser 2d and coming incontact with the cold walls ci the primary low temperature reirigeratingchamber, thegas will he condensed to a liquid and collect in the lowerreservoir. When the pressure equalizes due to the complete evaporationor the secondary refrigerant, the secondary refrigerant which has beencondensed `will again run into and illl the evaporator d'8. I

The amount or heat removed from the refrigerator lilI can he controlledin a simple manner by controlling the operation oi the ianfll or 'themotor it in the first embodiment. rEhe rotation oi the motor permitspassage oi the secondary refrigerant vapor through the cycle and whenretarded, the transfer of heat to the low tenperature primaryrefrigerant is retarded.

The cycle of secondary refrigerant is conm tinuous and automatic whilethe primary rem irigerant lasts. For continuous operation oi the motorit or suitable ily vvheelsand other devices may he round desirable. 'Eheincrease of heat removal at the higher emperatures oi reirigeratingchamber may maire desirabieunder certain conditions to cool the chamberin two Istages and especially is 'this true with air conm ditioning orin other applications where it is desirable to cool large volumes atrelatively high initial temperature.

While l have shown and described preerred y forms oi embodiment oi royinvention to be understood that the entire apparatus is shown asdiagrammatic to illustrate the application oi my invention and that manyrenements of heat exchangenature could be used without in any sensedeparting from the scope oi my invention. l therefore desire a broadinterpretation ci my invention Within the scope and spirit or" thedisclosure herein and of the claims appended hereinciter.

I claim:

i. A refrigerating circuit including a low tercperature refrigerantsource or the class voi solid carbon dioxide, an intermediatereirig'erating circuit energized by the heat oa substance to be cooled,and a compression refrigeration circuit effecting additionalrefrigeration of the substance to be cooled, said compressionrefrigeration circuit being energized by the flow of heat through saidintermediate circuit from the substance to be cooled to the lowtemperature refrigerant source, the characteristic of said jointrefrigerating circuits being such that the total refrigerationtheoretically available increases as the temperature of the substancetobe cooled is increased.

2. 'in a heat exchange apparatus oi the rcirigeration type for a chamberto cooled, the combination of a receptacle adapted. .to contain a lowtemperature refrigerant, a low helling point refrigerant in heatexchange relation with a re irigerant in said low temperaturerefrigerant re ceptacle, and adapted to be condensed thereby, evaporatormeans Within said chamber to evaporate said low. boiling pointrefrigerant by the heat of the contents oi said chamber, and a primemover receiving said evaporated refrigerant to convert the heat energyor the evaporated reirigerant to mechanical energy, means to dissipatesaid mechanical energy, whereby heat energy is removed from said chamberin addition to that absorbed by said low temperature refrigerant, saidmechanical energy dissipating means increasing eiectiveness of said lowtemperature refrigerant.

3. rI'he method of cooling large volumes oi niete ter at relatively hightemperature with a low temperaure refrigerant of the class or" solidcarbon dioxide which comprises condensing a low boiling pointrefrigerant hy heat exchange with the solid carb-on dioxide, expandingthe condensate in heat exchange relation the large volume oi matter toproduce cooling therein, converting the heat energy -to mechanicalenergy in a heat engine, converting said mechanical energy toreirigeration energy and additionally cooling the large volume of matterby said refrigeration,

in a heat exchange apparatus oi' the refrigeration type for a chamber tobe cooled 'the combination oi a receptacle adapted to contain a lov,rtemperature refrigerant, a condenser in heat exchange relation with thecontents of the receptacle adapted to condense a low boiling pointrefrigerant, an evaporator in heat exchange relation with the contentsoi said chamber to evaporate said low h oiiing point refrigerant, saidevaporator being connected to receive reirigerant from said condenser, apressure type prime mover, L

means to conduct the evaporated low boiling point refrigerant in. vaporphase to and through said prime mover and from the prime mover to thecondenser, and means to dissipate the energy ci said prime mover outsideof the chamber and independent oi the circulating lov; temperaturerefrigerant.

5. In a heat exchange apparatus of the reirigeration type for a chamberto be cooled the combination of a receptacle adapted to contain a lowtemperature refrigerant, a condenser in heat exchange relation with thecontents orn the receptacle adapted' to condense a low boiling pointrefrigerant, an evaporator in heat exchange relation with the contentsof said chamber to evaporate said low boiling point refrigerant, apressure type prime mover, means to conduct the evaporated low boilingpoint refrigerant in vapor phase to and through said prime mover andfrom the prime mover to the condenser, and means to dissipate the energyof said prime mover to the atmosphere outside of the chamber to becooled.

6. In a heat exchange apparatus ofthe refrigerationtype for a. chamberto be cooled the combination or a receptacle adapted to contain a lowtemperature refrigerant, a condenser in heat exchange relation with thecontents of the receptacle adapted to condense a low boiling pointrefrigerant, an evaporator in heat exchange repate the energy oi' saidprime mover comprising a compressor refrlgerating machine having acompressor, a. condenser and an evaporator, only said evaporator beingwithin the chamber and means to drive said compressor from said primemover.

7. In a heat exchange apparatus of the refrlgeration type for a chamberto be cooled the combination of a receptacle adapted to contain a lowtemperature refrigerant, a condenser in heat' exchange lrelation withthe contents of the receptacle adapted to condense a low boiling pointrefrigerant, an evaporator in heat exchange relation with the contentsof said chamber to evaporate said low boiling point refrigerant, apressure type prime mover arranged to be driven by the flow of heat fromthe chamber to the low temperature refrigerant and a compression typerefriger'ating apparatus operated by said prime mover and comprising asecond low boiling refrigerant.

- 8. The method of increasing the refrigerative eifect of a lowtemperature refrigerant which consists in utilizing the flow of heatfrom the space or material to be cooled to said low temperaturerefrigerant to operate a prime mover and in applying ythe work producedby said prime mover to operate a supplementary refrigeration machine tocool said space or material additionally.

9. The method of increasing the refrigerative eifect of a lowtemperature refrigerant which consists in abstracting heat from thespace `or material to be cooled by the evaporation of a low boilingrefrigerant in heat exchange relation therewith, utilising the vaporthus formed as the motive uid in al expansion engine, condensing saidvapor at low pressure by placing it in heat exchange relation with saidlow temperature refrigerant, and utilizing the work produced by saidexpansion engine to operate a supplementary compression refrlgeratingsystem to cool said space or material additionally.

10. In-a heat exchange apparatus of the refrigeration type for a chamberto be cooled the combination of a receptacle adapted to contain a lowtemperature refrigerant, a condenser in heat exchange relation with thecontents of the re-r ceptacle adapted'to condense a low boiling pointrefrigerant, an evaporator in heat exchange rela'- tion with thecontents of said chamber to evaporate said low boiling pointrefrigerant, said evaporator being positioned at al lower lever than thecond'enser and the condenser and evaporator being arranged to provide agravity circulation of the low boiling point refrigerant, a pressureprime mover, means to conduct the evaporated low boiling' pointrefrigerant in vapor phase to and through said prime'mover and from theprime mover to the condenser, and means todissipat'e the energy of saidprime mover to the atmosphere outside of and independent of said cham.-

11..'1he method -of increasing the refrigerative .eii'ect of a lowtemperature refrigerant which perature refrigerant to operate a primemover and in applying the work producedby said prime mover to operate asupplementary refrigeration machine.

12. The combination, with a compartment to b e cooled, of a receptaclefor receiving solid/car.- bon dioxide and mechanism4 arranged tocirculate a low boiling point refrigerant in heat exchange relation withsaid receptacle and in heat exchange relation with the air in saidcompart- -ment; said mechanism being made up of a circuit includingapressure type prime mover and means to bring about a flow of saidrefrigerant in vapor phase to said prime mover at the maximum pressurein the circuit and from said prime mover at the minimum pressure in thecircuit to `operate said prime mover.

13. The combination, 'with a compartment to be cooled, of a receptaclearranged to hold a charge of carbon dioxide adjacent said compartment,and a systemfor removing from said compartment energy over and abovewhatever energy may be expended in vaporizing said carbon dioxide; saidsystem comprising an engine, a power dissipating device disposed outsideof said compartment, means connecting said engine with said device and acircuit permanently charged with a secondary refrigerant and arrangedwithin said compartment; said circuit including a condenser insulatedfrom the interior of said compartment and disposed in heat exchangerelation with said receptacle, means for receiving liquid from saidcondenser, evaporating the same and supplying the resulting vapor tosaid engine and means for returning the discharge from said' engine tosaid condenser.` f

14. In the art of operating a cyclic system for cooling a refrigeratedspace, the method of utilizing the potential energy of an expandingsaturated vapor to operate a prime mover which comprises the steps ofcondensing the vapor by g heat .exchange with a low temperaturerefrigerant, vaporizing said 'liquid by heat exchange with the contentsof the space to be refrigerated, converting heatl energy to mechanicalenergy by expanding said vapor'in a prime mover and again condensing thevapor by heat exchange with a low temperature refrigerantandtra-nsferring the work of said prime mover outsidey of therefrigerated space.

15. The method of increasing the effective refrigeration of a chambercooled by a low temperature refrigerant: said method comprisingcyclically condensing, by heat exchange with the low temperaturerefrigerant, vapor of a secondary refrigerant; vaporizlng the resultingliquid by heat exchange with the air of the space to be refrigerated;expanding saidvapor in a heat engine and returning said expanded vapor.to be condensed in the succeeding cycle of operation; transferring thepower developed by the operation of said engine to a point outside ofsaid space and-at such point utilizing the power to propel a thirdrefrigerant through a compression-condensation evaporation cycleandutilizing the evaporation of the last mentioned refrigerant to absorbheat from said space.

16. 'Ihe combination with a refrigerator cabinet having ya storagechamber and a low tem-` perature refrigerant receptacle, ofrefrlgerating apparat for cooling the air in said chamber comprising anevaporator in said chamber, a condenser in said refrigerant receptacle,and an expansion engine, said evaporator, expansion engine and condenserbeing connected to form a circuit fr a 10W boiling point refrigerantWhelein the vapor of said low boiling point Iege'ant .mmed in theevaporator passes through the expension engine to the condenser and iscon dense@ thelein and Ieturned 30 the eveporefino? meeclenem mesme@melide o JIlm? storage chamba? im' absorbing and dssipating the workdone by said expansion engine and mechanical means te menseT the wml;done by said engine to the mechanism Rbsmbmg and dssipatmg means outside of the Teigera'iae emmETeI.

@Mm H.

CERTIFICATE @I1 CORRECTIONc atent NoD y291175,26??

i v DAVD 'It is hereby certified that eIwroId @011mms lne- 5, claim 69after the comme. smdbefore article means 'to conduct;- lI/Ie 6l,

October l0 g 1959 D 'ICL LLEETER u appears in che printed Specification0I" the eboxe'nvmbered patent requiring Correction as follows:

Page 5p first N the Y ins e 111'.;

claim l0:l for lever read level; and. that 'the Sad. Letters Patentshould. be reed with 'this c'onzeeton 'therein that the Helm? van del eI,

seme may conform' "so the record of the cese i1; the Patent OfficeuSigne@ end sealed this 5th 0I Deeem'berg A: Dc 195% (Seam ActingCommissioner of Patenten

